42 
Microscopically, the greater part of the section con- 
sists of closely-placed dense, pink, hyaline trabec- 
ulse containing lacunae or osteoblasts. Many of 
them are calcified. The intervening tissue con- 
sits of loosely-arranged round cells and fibroblasts. 
2669. Striped Hyena (Hycena hycena) : 
Carcinoma simplex of th^Toid. 
The greatly-enlarged th^Toid gland approximates 
the size of a croquet ball. The gland is irregular 
in shape, showing knob-like elevations containing 
a bloody grumous material. It is continuous with 
a clot of blood which can be traced upward around 
the esophagus and trachea and which by pressure 
caused the death of the animal. 
Microscopically, the section consists, for the most 
part, of white fibrous tissue, whose fibers are often 
separated by smaller or larger areas of hemorrhage. 
At one end of section a homogeneous polychro- 
matic material is seen, ribbed and torn as if by 
resistance to knife. Wliat little lining epithelium 
is present is regular in its stratification and does 
not seem to be especially proliferative. Outside 
of this homogeneous material the tissue is infil- 
trated with small round cells, between which 
often appears again this polychromatic material. 
The small round cells alluded to, for the most 
part have no relation to the basement membrane. 
They can be traced in some places to positions 
where they are arranged in strips as lining acini. 
In such places especially there is a predominance 
of this polychromatic material. 
2705. Undulated Grass Parrakeet (Melopsittacus un- 
dulatus) : 
Medullary carcinoma simplex of thyroid. 
On opening the body cavity a mass 10 x 6 x 4 mm. 
is found in the upper thoracic region on the right 
side. A similar mass, measuring 5x3x2 mm. 
